1. Field of the Invention
The invention generally relates to the integration of circuit components under a bond pad and more particularly, integration of deep trench mesh, CMOS, bipolar, and bipolar-CMOS (BiCMOS) structures and/or radio frequency (RF) passive structures under a bond pad.
2. Description of the Related Art
Radio frequency (RF) applications exist consisting of CMOS, bipolar, and bipolar-CMOS (BiCMOS) technology. In RF technology, a large number of different devices can be constructed. In CMOS technology, MOSFET transistors, resistors and diodes are constructed. In bipolar technology, bipolar transistors are formed. In bipolar CMOS technology, both MOSFETS and bipolar elements are formed. In Silicon Germanium (SiGe) devices, germanium is introduced into the base layer of an otherwise all-silicon bipolar transistor which creates significant improvements in operating frequency, current, noise, and power capabilities. At the same time, the key advantages of a state-of-the-art, 200 mm silicon process are maintained, including high integration level and economy of scale.
These high-performance technologies include both active and passive elements. CMOS technology consists of primary MOSFETs. RF-CMOS contains both RF passive elements and MOSET elements. RF BiCMOS SiGe Heterostructure Bipolar Transistors (HBT) technology include multiple SiGe HBT devices, and include passive elements such as transmission lines, inductors, capacitors, and resistors. Both RF CMOS and RF BiCMOS SiGe structures have applications in wireless communications and data-conversion components. RF CMOS has applications for wired and wireless application space such as cell phones, Blue tooth, Wi-Fi and other wireless applications. RF BiCMOS SiGe technology have further applications with products such as inexpensive safety systems for automobiles, including radar for collision warning or advanced cruise control; wireless voice and data handsets, with both RF and digital subsystems on a single chip; high-speed A/D and D/A converters for data acquisition, direct-to-baseband radio receivers; and low-cost, portable Global Positioning Satellite (GPS) receivers.
However, conventionally these RF circuit component structures are not placed under bond wire pads for RF CMOS and RF BiCMOS SiGe. In particular, they are not placed under bond wire pads for two physical reasons. First, when you apply pressure to the bond wire onto the pads, you can change the device characteristics by the physical pressure that is applied to the device. Second, mechanical problems or stress can crack the insulators in the pad. In such a case it is possible to actually crack or what is called singe around the device itself. Such problems will impact the integrity of the product. Moreover a crack has the negative effect of allowing humidity to get into the strip and additionally can result in leakage problems or damaged devices.